According to Gwen Stefani, she was a little anxious at first when boyfriendBlake Shelton surprised her with their duet, “Go Ahead and Break My Heart,” and asked to collaborate with her. Speaking with Chelsea Handler on the comedienne’s new Netflix series, the No Doubt frontwoman admitted she was worried about not liking Shelton’s song after he had sent her a demo.

“The story is that he had written this song and sent it to me on my phone. He’s like, ‘I wrote this song.’ And I was like, ‘Whoa, what if I don’t like it? Huge turnoff!'” Stefani, 46, said. Luckily, the singer fell in love with it after hitting play.

“I listened to it and thought, Oh, my God, I love this. He said, ‘Write the rest of it,'” she continued.

“There was a time when I was really insecure about writing,” Stefani explained. “There was such a drought of time when I was so insecure. I think when you have a really long year, you start to compete with your own self and get insecure.”

“I know that I don’t co-write that much because I’m very insecure about it I guess and [Stefani’s] kind of got her circle of people that she writes with. But for us to reach out to each other as writers, it may never happen again, who knows,” he told Entertainment Tonight. “I hesitate to brag on it too much but I really think that it’s as good of a song as I’ve ever written in my life.”